[Intel-gfx] [PATCH 2/2] drm/i915: drpc debugfs update for gen6

[Ben Widawsky]

On Wed, Nov 23, 2011 at 11:32:31AM -0200, Eugeni Dodonov wrote:
> On Tue, Nov 22, 2011 at 20:58, Ben Widawsky <ben at bwidawsk.net> wrote:
> 
> > Many of the old fields from Ironlake have gone away. Strip all those
> > fields, and try to update to fields people care about. RC information
> > isn't exactly ideal anymore. All we can guarantee when we read the
> > register is that we're not using forcewake, ie. the software isn't
> > forcing the hardware to stay awake. The downside is that in doing this
> > we may wait a while and that causes an unnaturally idle state on the
> > GPU.
> >
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42578
> > Cc: Eugeni Dodonov <eugeni.dodonov at intel.com>
> > Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> >
> 
> For both patches:
> Reviewed-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
> 
> Just one comment below.
> 
> 
> > +       if (count == 50)
> > +               DRM_INFO("Couldn't get accurate RC information\n");
> >
> 
> Maybe we should seq_printf() this as well? Like, for example:
> 
> seq_printf(m, "RC information accurate: %s\n", yesno(count != 50));
> 
> So the userspace consulting this file would know if it should rely on the
> values or retry the read..
> 
> Just an idea.

It's a good idea... I should almost definitely do that since the
information is *almost* definitely incorrect (unless we got really lucky
and the bit flipped after we gave up).

Also on second thought, I should probably check if user forcewake is
set, in which case I can recommend they unset it before reading the
value.

I'll redo this.

Thanks.
Ben